TESTING/LIN/dgbt02.f(3)    Library Functions Manual    TESTING/LIN/dgbt02.f(3)

NAME
       TESTING/LIN/dgbt02.f

SYNOPSIS
   Functions/Subroutines
       subroutine dgbt02 (trans, m, n, kl, ku, nrhs, a, lda, x, ldx, b, ldb,
           rwork, resid)
           DGBT02

Function/Subroutine Documentation
   subroutine dgbt02 (character trans, integer m, integer n, integer kl,
       integer ku, integer nrhs, double precision, dimension( lda, * ) a,
       integer lda, double precision, dimension( ldx, * ) x, integer ldx,
       double precision, dimension( ldb, * ) b, integer ldb, double precision,
       dimension( * ) rwork, double precision resid)
       DGBT02

       Purpose:


            DGBT02 computes the residual for a solution of a banded system of
            equations op(A)*X = B:
               RESID = norm(B - op(A)*X) / ( norm(op(A)) * norm(X) * EPS ),
            where op(A) = A or A**T, depending on TRANS, and EPS is the
            machine epsilon.
            The norm used is the 1-norm.

       Parameters
           TRANS

                     TRANS is CHARACTER*1
                     Specifies the form of the system of equations:
                     = 'N':  A    * X = B  (No transpose)
                     = 'T':  A**T * X = B  (Transpose)
                     = 'C':  A**H * X = B  (Conjugate transpose = Transpose)

           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           KL

                     KL is INTEGER
                     The number of subdiagonals within the band of A.  KL >= 0.

           KU

                     KU is INTEGER
                     The number of superdiagonals within the band of A.  KU >= 0.

           NRHS

                     NRHS is INTEGER
                     The number of columns of B.  NRHS >= 0.

           A

                     A is DOUBLE PRECISION array, dimension (LDA,N)
                     The original matrix A in band storage, stored in rows 1 to
                     KL+KU+1.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,KL+KU+1).

           X

                     X is DOUBLE PRECISION array, dimension (LDX,NRHS)
                     The computed solution vectors for the system of linear
                     equations.

           LDX

                     LDX is INTEGER
                     The leading dimension of the array X.  If TRANS = 'N',
                     LDX >= max(1,N); if TRANS = 'T' or 'C', LDX >= max(1,M).

           B

                     B is DOUBLE PRECISION array, dimension (LDB,NRHS)
                     On entry, the right hand side vectors for the system of
                     linear equations.
                     On exit, B is overwritten with the difference B - A*X.

           LDB

                     LDB is INTEGER
                     The leading dimension of the array B.  IF TRANS = 'N',
                     LDB >= max(1,M); if TRANS = 'T' or 'C', LDB >= max(1,N).

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (MAX(1,LRWORK)),
                     where LRWORK >= M when TRANS = 'T' or 'C'; otherwise, RWORK
                     is not referenced.

           RESID

                     RESID is DOUBLE PRECISION
                     The maximum over the number of right hand sides of
                     norm(B - op(A)*X) / ( norm(op(A)) * norm(X) * EPS ).

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 147 of file dgbt02.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0         TESTING/LIN/dgbt02.f(3)